- Radical C?H Trifluoromethoxylation of (Hetero)arenes with Bis(trifluoromethyl)peroxide
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Trifluoromethoxylated (hetero)arenes are of great interest for several disciplines, especially in agro- and medicinal chemistry. Radical C?H trifluoromethoxylation of (hetero)arenes represents an attractive approach to prepare such compounds, but the high cost and low atom economy of existing .OCF3 radical sources make them unsuitable for the large-scale synthesis of trifluoromethoxylated building blocks. Herein, we introduce bis(trifluoromethyl)peroxide (BTMP, CF3OOCF3) as a practical and efficient trifluoromethoxylating reagent that is easily accessible from inexpensive bulk chemicals. Using either visible light photoredox or TEMPO catalysis, trifluoromethoxylated arenes could be prepared in good yields under mild conditions directly from unactivated aromatics. Moreover, TEMPO catalysis allowed for the one-step synthesis of valuable pyridine derivatives, which have been previously prepared via multi-step approaches.
- Dix, Stefan,Golz, Paul,Schmid, Jonas R.,Riedel, Sebastian,Hopkinson, Matthew N.
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supporting information
p. 11554 - 11558
(2021/07/09)
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- Mild oxidation of benzyl alcohols to benzyl aldehydes or ketones catalyzed by visible light
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Induced by visible light, mild oxidation condition to prepare benzyl aldehydes or ketones have been developed by using bromotrichloromethane as photochemical oxidant. This method avoids high temperature, pressure and peroxidation with only visible light as the green driving force.
- Cheng, Dongping,Li, Xiaonian,Ren, Shujian,Xu, Xiaoliang
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supporting information
(2021/07/02)
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- Photocatalytic trifluoromethoxylation of arenes and heteroarenes in continuous-flow
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The first example of photocatalytic trifluoromethoxylation of arenes and heteroarenes under continuous-flow conditions is described. Application of continuous-flow microreactor technology allowed to reduce the residence time up to 16 times in comparison t
- Cendón, Borja,Gulías, Moisés,Ho, Michelle,No?l, Timothy,Nyuchev, Alexander V.,Sambiagio, Carlo,Struijs, Job J. C.,Wan, Ting,Wang, Ying
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supporting information
p. 1305 - 1312
(2020/07/10)
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- Radical Trifluoromethoxylation of Arenes Triggered by a Visible-Light-Mediated N?O Bond Redox Fragmentation
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A simple trifluoromethoxylation method enables non-directed functionalization of C?H bonds on a range of substrates, providing access to aryl trifluoromethyl ethers. This light-driven process is distinctly different from conventional procedures and occurs through an OCF3 radical mechanism mediated by a photoredox catalyst, which triggers an N?O bond fragmentation. The pyridinium-based trifluoromethoxylation reagent is bench-stable and provides access to synthetic diversity in lead compounds in an operationally simple manner.
- Jelier, Benson J.,Tripet, Pascal F.,Pietrasiak, Ewa,Franzoni, Ivan,Jeschke, Gunnar,Togni, Antonio
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supporting information
p. 13784 - 13789
(2018/09/14)
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- TEMPO-mediated oxidation of primary alcohols to aldehydes under visible light and air
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A homogeneous visible light photoredox TEMPO-mediated selective oxidation of primary alcohols to the corresponding carbonyl compounds was developed using molecular oxygen from air as the terminal oxidant. Ru(bpy)3(PF 6)2 (bpy: bipyridyl) and Ir(dtb-bpy)(ppy) 2(PF6) (dtb-bpy: 4,4′-di-tert-butyl-2,2′- bipyridyl; ppy: 2-phenylpyridine) were used as the sensitizers. A homogeneous visible light photoredox TEMPO-mediated selective oxidation of primary alcohols to the corresponding carbonyl compounds was developed. Molecular oxygen from air was the terminal oxidant. Copyright
- Liu, Dongwang,Zhou, Hongxia,Gu, Xiangyong,Shen, Xiaoqin,Li, Pixu
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supporting information
p. 117 - 122
(2014/03/21)
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- Process for preparing benzyl alcohols and their use
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Benzyl alcohols, particularly those which bear fluorine substituents or fluoroalkyl substituents on the benzyl ring, can be obtained by formylation of corresponding aryl bromides to form benzaldehydes and reduction of the latter using further formate, wherein the benzaldehydes formed do not have to be isolated.
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- 2-, 3-, and 4-(Trifluoromethoxy)phenyllithiums: Versatile intermediates offering access to a variety of new organofluorine compounds
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Consecutive treatment of (trifluoromethoxy)benzene with sec-butyllithium and electrophilic reagents affords previously inaccessible ortho-substituted derivatives in generally excellent yields. 2-(Trifluoromethoxy)phenyllithium acts as the key intermediate. The 3- and 4-isomers can readily be generated from the corresponding 3- and 4-bromo precursors by halogen-metal interconversion with butyllithium or tertbutyllithium. Upon trapping of the 2-, 3- and 4-(trifluoromethoxy)phenyllithiums with 11 different electrophiles the expected products were formed in generally high yields. Only the attempted nucleophilic addition of 2-(trifluoromethoxy)phenyllithium to oxirane did not succeed. This failure is tentatively attributed to a lowering of the nucleophilicity by fluorine-lithium interactions. Conformationally restricted analogs - i.e., 2,2-difluoro-1,3-benzodioxol-4-phenyllithium and its 5-fluoro- and 5-bromo-substituted congeners - did indeed react smoothly with oxirane, affording the adducts in ordinary yields.
- Castagnetti, Eva,Schlosser, Manfred
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p. 691 - 695
(2007/10/03)
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- A liquid crystalline compound containing fluorine atom substituted alkyl group(s) and a liquid crystal composition
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A liquid crystalline compound exhibiting a large Δ ε value, an electrical and chemical stability and a superior compatibility with existing liquid crystalline compounds, a liquid crystal composition containing the same, and a liquid crystal display element constructed by using the composition are provided,???which liquid crystalline compound is expressed by the formula (I), F-(CH2)n ―E-(CH2CH2) k―G-(CH2CH2)l―L-(CH2CH2) m―Z―Q―Y wherein n is an integer of 1 to 10; k, l and m each independently are an integer of 0 to 2; ring E is 1,4-cyclohexylene group or 1,4-phenylene group, wherein one or more H atoms on six-membered ring may be replaced by F atom(s); G and L each independently is a covalent bond or 1,4-cyclohexylene group or 1,4-phenylene group, wherein one or more H atoms on six-membered ring may be replaced by F atom(s); Q is covalent bond or -O-; Y is a fluoroalkyl group of 1 to 3C or F atom; but in the case where ring E is 1,4-cyclohexylene group and at least one of G and L is covalent bond, and in the case where Q is -O-, Y is not F atom.
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- Heterocyclic pesticidal compounds
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Compounds of the formula (I) STR1 which contain between 10 and 27 carbon atoms, and wherein m and n are independently selected from 0, 1 and 2; R2a is hydrogen, methyl, or ethyl; R2b is acetylene or contains between 3 and 18 carbon atoms and is a group R7, wherein R7 is a C1-13 non-aromatic hydrocarbyl group, optionally substituted by a cyano or C1-4 carbalkoxy group and/or by one or two hydroxy groups and/or by one to five halo atoms which are the same or different and/or by one to three groups R8 which are the same or different and each contain one to four hetero atoms, which are the same or different and are chosen from oxygen, sulphur, nitrogen and silicon, 1 to 10 carbon atoms and optionally 1 to 6 fluoro or chloro atoms or R2b is a 6-membered aromatic ring substituted by cyano and/or by one to three groups R8 and/or by a group --C CH, --C C-R7 or C C-halo and/or by one to five halo atoms and/or by one to three C1-4 haloalkyl groups wherein R7 and R8 are as hereinbefore defined; R4 and R6 are the same or different and are chosen from hydrogen, methyl, trifluoromethyl or cyano; and R5 is hydrogen or methyl provided that R2b is not propyl or butyl are described which have pesticidal activity, particularly against arthropod pests. Pesticidal formulations containing the compounds of the formula (I), their use in the control of pests and method for their preparation are also disclosed.
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- Insecticidal compounds
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Insecticidal and acaricidal compounds of formula: STR1 and stereoisomers thereof, where R1 represents C1-4 alkyl, R2 represents H, CN, CH3, or CF3 ; Q represents CH or N; and Z represents one or more substituents selected from fluoro, benzyl, phenoxy and halophenoxy.
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- Insecticidal compounds
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Insecticidal and acaricidal compounds of formula: STR1 and stereoisomers thereof, where R1 represents C1-4 alkyl, R2 represents H, CN, CH3, C CH or CF3 ; Q represents CH or N; and Z represents one or more substituents selected from fluoro, benzyl, phenoxy and halophenoxy.
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- Process for preparing aromatic aldehydes
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Aromatic aldehydes are prepared by formylating the corresponding aromatic compounds with urotropine in the presence of hydrogen fluoride. By the described process certain new aromatic aldehydes can be prepared.
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- Acylation du trifluoromethoxybenzene en catalyse HF-BF3
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Friedel and Crafts acylation of trifluoromethoxy- and trifluoromethyl-thiobenzene fails to give ketones in a one step synthesis if chlorinated Lewis acids (AlCl3) are used, because of halogen exchange on the -OCF3 and -SCF3 groups.The use of a fluorinated catalyst system such as HF-BF3 avoids exchange reactions and acylation occurs smoothly under mild conditions: - Low temperature and pressure - High yields (very often >90 percent) - Very high para-regioselectivity.Related reactions such as formylation or sulfonylation can also be achieved under similar conditions.
- Desbois, Michel
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p. 885 - 890
(2007/10/02)
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- Antimalarials. Synthesis and antimalarial activity of 1 (4 methoxycinnamoyl) 4 (5 phenyl 4 oxo 2 oxazolin 2 yl)piperazine and derivatives
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The preparation and activity against Plasmodium berghei of derivatives of 1 (4 methoxycinnamoyl) 4 (5 phenyl 4 oxo 2 oxazolin 2 yl)piperazine are described. Replacement of the cinnamoyl group was accomplished by acylation or alkylation of 1 (5 phenyl 4 oxo 2 oxazolin 2 yl)piperazine. Modifications of the 5 phenyl group were prepared either by a sequence of reactions involving mandelic ester pemoline piperazine pemoline or by the reaction of 5 aryl 2 thio 2,4 oxazolidinedione with piperazine or N substituted piperazines. In a similar manner, pemoline was allowed to react with N arylpiperazine, hexahydro 1H 1,4 diazepine, and 2,6 dimethylpiperazine to provide N arylpiperazine pemoline derivatives and variations in the piperazine moiety. Several compounds in which the 2 oxazolin 4 one ring was replaced with other heterocyclic rings were prepared as were several open chain analogs. Five compounds (three of them substituted in the para position of the 5 phenyl group and two N arylpiperazine pemoline derivatives) were found to be active against Plasmodium berghei. The remaining active compound possessed changes in the cinnamoyl group and substitution on the 5 phenyl group.
- Herrin,Pauvlik,Schuber,Geiszler
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p. 1216 - 1223
(2007/10/04)
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